Do I Need A Special Thermostat For Gas Fireplace?

Gas fireplaces are a wonderful improvement on traditional wood-burning fireplaces, with added safety and user control. These heating systems can even be controlled via a thermostat. If you're thinking of installing a thermostat for your gas fireplace, you may be wondering if you need a special type. We've done the research to give you an answer.

No, gas fireplaces are very versatile and can be used with any type of thermostat, switch, or remote control. However, when you want a thermostat to control a gas fireplace, a millivolt type is best for ease of installation and overall functionality. 

Now you know that a millivolt thermostat is best for your gas fireplace, though it is possible to use any type that you have on hand. You may desire more details, including how to install and set a thermostat connected to a gas fireplace. Keep reading to learn more.

gas fireplace on gray wall burning for the cold of winter. Do I Need A Special Thermostat For Gas Fireplace

Types Of Gas Fireplace Controls

When it comes to this type of heating unit, you can use a few different types of controls. Each has its own benefits that make it best for some homes and not a good option for others.

Do I Need A Special Thermostat For Gas Fireplace


The most popular of controls for a gas fireplace is the simple "light switch." This can be used to turn the gas fireplace on when desired and turn it back off when its effects are no longer needed, just as easy as turning a light on and off.

While this may be attractive to some users, it may be too simple for others. If you do not use your gas fireplace as a heat source and only to create ambiance, this may be for you. Additionally, if you only plan to use your fireplace sparingly, it may be the most desirable option.

Remote control for air conditioner on wooden table

Remote Control

The remote is another option to consider. It can be programmed to connect directly to the fireplace, or it can be used as an extension of a switch or thermostat-based control.

The remote may be especially desirable for inhabitants who are less mobile, as they will not have to reach a thermostat or switch to have full control over the fireplace. However, they may seem like an unnecessary extension for some who would like to just have a stationary control center.

Man is Adjusting a temperature in modern living room


A thermostat will work for you by causing your gas fireplace to cycle on when the surrounding air has fallen below the set temperature. Then the thermostat will cause it to turn off when the surrounding air has met the set temperature.

This may be a great option if you desire to use your gas fireplace as a source of heat rather than just a source of ambiance. It will work to add heat to your home with minimal thought and effort.

What Is The Best Type Of Thermostat For Gas Fireplace?

The best type of thermostat for a gas fireplace is a millivolt. This type of thermostat uses a low amount of electrical voltage. Because of this, it is easy to install and use for a gas fireplace.

It does not require to be connected to the home's wiring system, and it will not need a step-down transformer. Even with this simplicity, millivolt thermostats include all of the ease-of-use settings. You can find them as digital, programmable, and smart thermostats.

Take a look at this millivolt thermostat on Amazon.

Does A Nest Thermostat Work With A Gas Fireplace?

Yes, the Nest thermostat is compatible with a gas fireplace, and what's more, it's a millivolt system! So it can be installed and used with ease.

Check out this Nest thermostat on Amazon.

Installing A Thermostat For Gas Fireplace

Installing a millivolt thermostat for a gas fireplace is a fairly simple process for a homeowner to complete. These instructions will guide you to install any millivolt thermostat to your gas fireplace, including the Nest. There are a few supplies you will need to be sure you have before beginning.


While other HVAC systems, including your central heating and air, support 24V AC, your gas fireplace does not. So you're going to have to do a little innovating. You can visit any of your local hardware stores and purchase a transformer. This attachment will enable your thermostat to switch the 24V AC source.

Take a look at this 24V AC transformer on Amazon.

The next purchase you will need to make is that of a fan relay. This will allow your gas fireplace to switch the millivolt system. Female spade terminals are also handy supplies to have on hand for this job. You need all of these items to ensure that the gas fireplace and thermostat connect properly.

Check out these female spade connectors on Amazon.


With your purchases made, you're ready to begin the process of connecting the thermostat to the fireplace. First, locate your existing thermostat wires and disconnect them. If desired, you can also turn off the electricity to the area. This is an electrical job, which always comes with a risk of injury.

It will then be time to install the AC adapter. Plug it into a convenient location, then run all of the wires to the thermostat unit's backplate. From here, connect one AC adapter lead to the thermostat unit's RH terminal. Tin the end of that lead.

Next, connect the other AC adapter lead to the red thermostat wire. Lastly, connect the white thermostat wire to the thermostat unit's W1 terminal. At this point, the AC adapter and thermostat unit are now connected.

The next step is to connect the fan relay between the gas fireplace and the thermostat unit. Locate the thermostat leads within the fireplace. Place the female spade terminals on two of these wires, as well as two wires from the thermostat unit.

Connect the thermostat unit wires to relay terminals 1 and 3. Then connect the fireplace thermostat leads to relay terminals two and four. Everything should now be connected, and it's time to test your work.

Turn on the electricity, plug in the adapter, and connect the thermostat unit to its backplate. Set the thermostat so that the gas fireplace will cycle on.

A fire burns in a glass fireplace, radiates heat

If you have completed the installation correctly, you will see that the thermostat is signaling to the fireplace to turn on and off. If not, there is most likely an unsecured connection that will have to be troubleshot and remedied.

How Do You Set A Thermostat On A Gas Fireplace?

Once you have your thermostat installed correctly, you may want to know how to set your gas fireplace for the best comfort and convenience. There are two ways to set your thermostat, either by temperature or by timer. We'll give you instructions on each method.

By Temperature

The temperature mode controls the gas fireplace by detecting the temperature of the surrounding air and signaling to the gas fireplace whether it should cycle on in order to heat the room or cycle off to allow the room to cool.

If you use your fireplace as a heat source during the frigid winter months, this may be the best option for you. Setting the thermostat to the temperature mode is a bit different between millivolt thermostats, but for our purposes, we will give you instructions based on the Nest thermostat.

First, press the "set" button. This will show your options, and you will choose the "sun" mode. On other thermostats, this may be the "temp" mode. Then set your desired temperature. After this has been done, wait five to ten seconds for the thermostat to finish programming or press the "off" button. That's it!

By Timer

When a thermostat is set to the timer mode, this causes the thermostat to signal the gas fireplace to cycle on at a certain point in time and cycle off at another point in time.

Perhaps you enjoy a few hours of a cozy fire in the evening but don't want to have to remember to turn it off before falling asleep on the couch or retiring to bed. Then this is for you!

To set your thermostat to timer mode, press the "set" button. This will show your options, and you will choose the "timer" mode. Press the set button again, and it will signal for you to choose a start time. Press it once more, and it will signal for you to choose an end time.

Related Questions

Now that we've addressed the most pressing issues around your gas fireplace, we thought we'd answer a frequently asked question that you may also have.

Is It OK To Leave The Pilot Light On A Gas Fireplace?

Leaving your pilot light on is not only OK, it actually has potential benefits. It will keep the firebox dry, and this is helpful in the humid spring and fall seasons. It also will keep cobwebs from collecting and blocking the pipes.

The final benefit is that you will not have to relight the pilot light in the winter months when you would like to use your gas fireplace again.

Biofireplace burn on ethanol gas. Contemporary mount biofuel on ethanol fireplot fireplace. Do I Need A Special Thermostat For Gas Fireplace

In Conclusion

Gas fireplaces are versatile in many ways, including the controls that can be used for them. Any type of thermostat can be connected to a gas fireplace, though millivolt thermostats are best for the job. These can help your gas fireplace supply heat and ambiance to your home all winter long.

Want to learn more about thermostat installation? Visit these related posts:

How To Move A Thermostat On The Same Wall

How To Move A Thermostat To Another Room

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